1. Field of the Invention
The present invention relates to a suspension-steering control apparatus in a four-wheel steering vehicle in which the rear wheels are steered together with the front wheels.
2. Description of Related Art
Heretofore, there is a suspension apparatus of a vehicle which alters its suspension characteristics to a harder or softer state by changing a damping force of a damper. For example, Japanese Utility Model Examined Publication (kokoku) No. 45,129/1983 discloses a suspension apparatus in which a suspension characteristic is changed during a high speed driving so as to allow the damping force of a damper on the front wheel side to be higher than on the rear wheel side, thereby understeering its steering characteristic and improving a driving stability.
It is also known that a four-wheel steering vehicle has a basic function of steering the rear wheels to a steering angle in accordance with a steering angle of the front wheels, when the front wheels are being steered, on the basis of a given rear-wheel steering characteristic preset with respect to the front wheels, the suspension characteristic being capable of being conveniently corrected. For example, Japanese Patent Unexamined Publication (kokai) No. 220,972/1986 discloses a suspension apparatus which corrects a steering characteristic on the same phase side as the front wheels during driving at a low speed, thereby improving cornering at the time of driving at a low speed.
As have been described hereinabove, for the four-wheel steering vehicle in which the suspension characteristic is variable, it is common that the suspension characteristic is changed independently from control over steering of the rear wheels.